Pulse translating mechanism



March 11, 1947.

W. E. NEWMAN PULSE TRANSLATING MEGHANI SM Filed March 2, 1944 3 Shets-Sheet 1 OFF MOTOB 15 or! M OFF on #0705 a name A 3 22.

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WILL/AM E. NEWMAN 8r g 7 M-zH i/ March 11, 1947. w. E. NEWMAN 2,417,376

PULSE TRANSLATING MECHANISM Filed March 2, 1944 s Sheets-Sheet 1 \fiqk Qwksn x $4 MEWEN w z w r x 0 K E a R r M w w w e 5 W M m wm Nu QMSQQMQ M NW NW a? M 51 m r K J? 5 a g MU m8 March 11, 1947. w. E. NEWMAN PULSE TRANSLATING MECHANISM s Sheets- Sheet 3."

Filed March 2.; 1944 l/IVE/W'OB. W/LL/AM E. NEWMAN 2%! ATTOB/VE'K Patented Mar. 11, 1947 UNITED STATES PATENT OFFICE to Radio Corporation of America,

tion of Delaware ,3 corpora- Application March 2, 1944, Serial No. 524,727

2 Claims.

My present invention relates to pulse translating mechanism for effecting independent control of a plurality of electrical devices, such as, motors, lamps, radio apparatus, etc., from a remote point.

One of the objects of the invention is to provide means whereby the operation and control of electrical apparatus at a remote point is effected by the transmission of electric pulses over conductors or by radio.

Another object resides in the use of pulse dial mechanism analogous to that used in automatic telephony adapted to transmit pulses to operate a selector switch for effecting the operation and control of radio apparatus or other electrical devices.

Another object resides in the provision of a solenoid-actuated ratchet wheel which does not require the customary second solenoid for returning the ratchet wheel to its normal, inoperative position.

A further object is the provision of a time delay device, Which may be mechanical or electrical, for effecting closure of a controlling circuit subsequent to the movement of the selector switch to a desired position thereby preventing th operation of devices other than the one presently desired to be operated and controlled.

A still further object is the provision of mechanism for performing a plurality of control functions, said mechanism comprising dial means at a control point for transmitting a plurality of pulses to a, remote point, the number of transmitted pulses depending upon the particular control function desired to be performed, functionselecting means at the remote point, means operable by said transmitted pulses for actuating the selecting means to select the desired control function, and a time delay device operative to prevent the selected control function from being performed until after actuation of the selecting means has been completed.

The novel features which I believe to be characteristic of my invention are set forth in particularity in the appended claims; the invention itself, however, both as to its organization and mode of operation together with further objects and advantages thereof, will best b understood by reference to the following description taken in connection with the accompanying drawing, in which:

Fig. i discloses schematically a pulse translate ing mechanism according to the invention for effecting the remotecontrol of certain electrical devices;

Fig. 2 discloses the application .of the invention to radio receiving apparatus for the remote control thereof; and

Fig. 3 discloses the use of a thermostatic time delay switch which may replace the mechanical time delay mechanism of Figs. 1 and 2.

Referring to Fig. 1, the devices to be controlled are shown, by way of example, to comprise a lamp L, a motor A and a second motor B. These devices are capable of selective control independently of each other, and any number of such devices may be so controlled. In the instant case, the lamp, and the motors which are of the reversible type, may be turned on or off in any desired sequence, and it is possible also to reverse at will the direction of rotation of each motor.

The several devices to be controlled, namely, motors A, B and lamp L, each have associated with it an on-oif relay R5, R2 and R3, respectively, and in addition a motor-reversing relay R4, R5 is associated with the motors A and B, respectively. The several relays are of similar construction, each comprising a pair of windings i l, 12 and an armature [3 adapted to rest against one or the other of two contacts Hi, l5, depending upon which one of the relay windings was previously energized. In the drawing, the contacts 14 of relays R9, R2 and R3 have been designated as on, contacts and the contacts N3 of the same relays as off contacts. With respect to the contacts It and it of relays R41 and R5, they have been; designated respectively as right and left. The'common terminal of windings ll, l2 of each of the relays RI, R2, R4 and R5 is connected to a conductor I 6 leading to one side ofa suitable source of power Bl, which is represented here in the conventional manner by a battery, although it is to be understood that an A. C. source may be employed, if desired.

A conductor l! is connected between the same sideof the source and the on contact M of relay R|,,R2, and a conductor 18 is connected between the source and. a terminal of lamp L, the other terminal of which is connected to the on contact it of relay R3. The armature l3 of the latter relay is connected by Way of conductor l9 to a conductor 29 leading to the other side of power source Bl. A conductor 2! connects together the armatures of the relays RI and R4, and a conductor 2! connects together the armatures of the relays R2 and R5.

The field windings 22, 23 of motor A are connectedat one terminal to respectively the right and left contacts M, 5 of relay R4 and the similarly-numbered field windings of motor B are connected at one terminal to respectively the similarlymumbered contacts on relay R5, the other terminals of each pair of motor field windings bein connected together and to the other side of the power source B! by way of a conductor 28' and the conductor 28.

At 24 there is shown a selector switch having a pivoted contact arm'25 which is adapted to be actuated always from a normal position, when at rest on a contact N, in a step-by-step manner to contacting relation with any one contacts numbered l to H. Contacts l and 2 are connected respectively to the individual terminals of windings H, l2 of the relay RI, similar connections being made between contacts 3, i and the windings of relay R2, between contacts 5, 6 and the windings of relay R4, between contacts 1, 8 and the windings of relay R5, and between contacts 9, In and the windings of relay R3. The end contact H is unconnected, defining the position to which the switch arm 25 isadapted to be stepped when it is desired that the switch arm be reset to its normal position, as will be explained more fully hereinafter.

A conductor 25 conductively connects the selector switch arm 25 to conductor 20, and interposed in the conductor 26 is a power-restoring switch 2?, the function of which will be described later. This switch is provided with a fixed contact 28 and a movable contact 29 which, in the absence of a force tending to move it to switchclosing position, is biased away from the fixed contact 28 by its inherent resilience.

The mechanism for stepping the selector switch arm 25 one step at a time in response to successive pulses will now be described. The switch arm 25 is carried on a shaft 30 which also carries a ratchet wheel 3 5. Suitable means such as a helical spring 32 is adapted, when permitted to do so, to urge or return the switch arm to its normal or inoperative position shown in Fig. 1, in contact with the unconnected contact N.

Associated with the ratchet wheel 3| is a U- shaped trip pawl 33 pivoted at 3 3 and provided with an arm 35 adapted to engage the teeth of the ratchet wheel and with a further arm 36 which is disposed in front of the ratchet wheel and in the path of a pair of suitably-spaced pins 3'l'and 38 carried on the face of said wheel. The trip paWl 33 is maintained in its operative position, as shown, by an over-center spring 33 havme one end connected to a pin 40 carried by the pawl and disposed below its pivotal point 3 1 and its other end connected to pin 4! afiixed to a suitable support. The function of the pin 3! is to release or disengage the part 35 of the pawl 33 from the ratchet wheel after the contact arm has been stepped to contact H. In that position of the arm the pin 31 will have been moved to abutting relation with the pawl part 36 and will exert sufficient force thereon to swing the pawl about its pivot 34 in a counter-clockwise direction to move part 3-5 away from the ratchet wheel, the over-center spring tending to complete said movement of the pawl which is limited by a stop pin 42.- The ratchet wheel 3i isnow free to move and will do so in a counter-clockwise direction due to the action of spring 32. The switch con tact arm also will be moved in the same direction and, just before it is returned to its normal or initial position on contact N, the pin 38 will co-act with the under-side of arm 36 to swing the pawl in a clockwise direction to reset the same to its operative, or ratchet wheel-engaging position, the over-center spring 39 now serving to re tain the pawl in that position.

The pawl for actuating the ratchet wheel is shown at 53 pivoted at one end to an extension member 44 affixed to a solenoid plunger d5. A spring 45 is connected between the other end of the pawl and 'a fixed support 4! and is adapted in its retracted condition to hold the pawl upwardly out of engagement with the ratchet wheel. A stepping solenoid s8 is adapted, when energized of a series of of the windings ll,

to pull its plunger 45 to the right as viewed in the figure, to similarly move the pawl 43 which is first obliged to move downwardly into engagement with the ratchet wheel by action of the spring 48. Such movement of the pawl in response to each stroke of the solenoid plunger is adapted to move the ratchet wheel through a distance equal to that between adjacent teeth which corresponds also to the distance between adjacent ones of the contacts N through i i.

The circuit for the stepping solenoid 48 contains a power source B2 and a pair of normallyopen contacts 49 located at a remote point, the contacts being connected to the solenoid winding and the source B2 by means of a two-wire cable In order that the requisite number of pulses may be transmitted to the stepping solenoid, there is provided a dial mechanism indicated generally at iii which is similar to that used in connection with automatic telephony. Constituting a part of this mechanism is a rotatable dial plate 52 of usual construction having eleven numbered apertures into any one of which the finger may be placed to rotate the dial in a clockwise direction until the finger is stopped by member53. The dial plate is then released and the same will return to its normal position by spring means (not shown) in a counter-clockwise direction. During the return movement of the dial plate the contacts tc will be closed to energize the solenoid a number of times in accordance with the number of the hole into which the finger had been placed to rotate the dial.

For the convenience of the operator, suitable legends may be applied to the disc plate. In the instant case, the holes numbered 1 and 2 will be designated, Motor A-On and Off, respectively; holes 3 and 4 as Motor B-On and Off, respectively; holes 5 and 6 as Right and Left, respectively, for Motor-A; holes 7 and 8 as Right and Left, respectively, for Motor B;

holes 9 and 10 as On and Oil, respectively, for the lamp I; and thehole numbered 11 will be designated bythe legend Reset.

In order to'prevent indiscriminate energization l2 of theseveral relays Rl to R5 in either direction of movement of the switch arm 25, there is provided a mechanical escapement or time delay mechanism 54, operatively associated with the plunger extension 44 for preventing the power-restoring switch 2'! from closing between pulses, but permitting the switch to close after the final pulse had been transmitted to thereby restore power to the circuit of the device sought to be controlled.

Although any suitable time delay mechanism may be utilized, the particular one that Ihave used and which I have chosen to disclose in Fig. 1 consists of a pinion 55 in meshing relation with a slidable rack bar 56 which is provided at one endwith a pin 51 arranged for sliding movement within a slot 58 formed at the free end of the plunger extension M. This slidable coupling between the rack and the solenoid plunger removes the load of the time delay mechanism from the solenoid plunger 0n the return stroke, so that the plunger can travel back and forth freely to impart rotation to the'ratchet wheel 3! through Q the pawl #13. A spring 59 supported between pins 50 and El carried respectively by the adjacent ends of the rack 56 and member 44 returns the solenoid plunger $5 to the left between pulses of current through the solenoid. At the other end of the rack, connected between a pin 62 and a fixedflsupport 63, is a spring 64 for driving the time delay mechanism and for returning the rack and plunger assembly to the neutral position at the extreme left after all the pulses have become effective. The rack is also provided at this end with a part 65 which serves to move the movable contact 29 of switch 2'. to switch-closing position.

The pinion 55 is mounted on a shaft 55 suitably journalled in a support 57. A gear 58 is free to rotate on the shaft 66 in a clockwise direction relatively to pinion 55, but is constrained to move together with the pinion in the reverse or counter-clockwise direction by action of a spring-pressed pawl 69 carried by gear 63 and urged by spring '10 to engage the teeth of pinion 55. Meshing with gear 68 and adapted to be driven thereby is a pinion II mounted on a shaft 12 also journalled in support 57. Rotating with said shaft is a crank arm 73 to which there is pivotally connected one end of a link i i, the other end of which is pivotally connected to a fiy-wheel 15 supported on a shaft 16 also journalled in support 61.

The operation of the mechanical time delay device 54, which it will be remembered, is to prevent premature closing of switch 27, is as follows: movement of the plunger and its extension to the right in response to the first of a series of current pulses through the solenoid will cause similar movement of the rack bar 56 to allow thereby the opening of switch 27. Except for the opposition of spring 54, the rack bar will not be hindered in its movement to the right since in that case only the pinion 55 is moved, its counterclockwise rotation causing the pawl to ride up and down about its pivotal point. On the return movement of the rack bar, however, upon the solenoid becoming de-energized, the rack bar will be pulled to the left by spring 64 and will cause clockwise rotation of pinion 55 in which case the gear 58 will be coupled to the pinion 55 by the locking action of pawl 59. The motion of gear 63 will then be transmitted through pinion I I, crank arm 13, and link 14 to the fly-wheel I5 which will oscillate back and forth through a distance represented by the arc 77. There is therefore imposed on the rack bar, during its return movement to switch-closing position, a load which tends to retard the closing of switch 21. In practice, the time delay mechanism is adjusted to hold the switch 27 open for an interval at least as long as it takes the switch contact arm 25 to advance to contact I I.

The operation of the system above described and disclosed in Fig. 1 is as follows: Let it be assumed first that the armatures I3 of the several relays are in the positions shown, in which case motors A and B are in the inoperative state and the light L is turned off. Let it be assumed further that it is desired to have the motor A set into operation and to rotate in the right direction. Asa preliminary step the dial plate 52 at the control point will be manipulated by placing the finger in hole 1 to dial Motor AOn. Contacts 49 will, therefore, be closed just once to pulse the stepping solenoid 48 to thereby advance the switch arm 25 to contact I. Simultaneously, the switch 21 will have been opened by movement of the rack bar 56 to the right, and after some delay as explained above, will again assume its closed position. Upon closure of said powerrestoring switch 27, the circuit of winding II of relay RI :ill be completed as follows: one side of source BI, conductor I6, winding II of relay RI, contact I, arm 25, conductor 26, closed switch 21, conductor 26, conductor 2.0,.and back to the other side of source BI. As a result, winding I I of the relay RI will be energized to throw its armature I3 against the On contact I4. This will cause operation of motor A but in the left direction, the motor circuit being closed from the plus side of BI, conductor IS, on contact I l of relay RI, its armature l3, conductor 2i, armature of relay R4, left contact I5, field winding ,23 of motor A, conductor 29', conductor 20, and back to the minus side of El.

,In order that the direction of motor operation may be reversed so that. it will rotate in the right direction, as assumed in the example given above, it is necessary first to have switch arm 25 brought back to its neutral or initial position on contact N from its previously set position on contact I. This is effected by dialing plate 52 of the dial mechanism to Reset. As a result stepping solenoid 48 is pulsed 11 times. The first 1O reset pulses are effective .to actuate ratchet wheel 3! in a clockwise direction and to cause switch arm 25 to he stepped along from contact. to contact II. At the corresponding position of the ratchet wheelthe pawl release pin 37 coacts with arm 38 .to throw the trip pawl 33 out of engagement with the ratchet wheel, but the latter is not yet free to return to its initial position because the eleventh pulse, which is received immediately after the trip. pawl is thrown at the tenth pulse, actuates the stepping pawl to engage the ratchet wheel Which is thereby for that instant arrested in its return movement. After receipt of the eleventh pulse the stepping pawl is retracted to its inactive position and the ratchet wheel is thenpermitted to return under the influence of spring 32 to its initial position, whereat switch contact arm 25 rests on contact N and ratchet wheel BI is again engaged by the pawl part 35 having been moved to engaging position by coaction of reset pin 33 against arm 3.5.

Regardless. of the position of switch arm on any of the contacts I to I ii to which it had previously been stepped to effect a desired function, subsequent operation of the dialing mechanism to Reset results in the switch arm being stepped along to contact Ii by the number of pulses necessary to do so, after which the ratchet wheel is arrested its return movement, as explained above, for the duration of the remaining reset pulses. After the eleventh or final pulse the return spring 32 is effective to rotate the switch arm back to contact N. The mechanism is then set fora new cycle of operation.

To complete the operation, that is, to reverse motor A, the dial plate 52.is then dialed Motor Aright (hole 5), with the result that the switch arm will he stepped along to contact 5, it being remembered that the switch 2? was first opened by movement. of the rack 55 to the right during the stepping action of the switch arm and later closed after the lapse of an appreciable interval. .With the switch arm on contact 5 and the switch 27 closed, a circuit is completed through the winding I I of relay R4 as follows: one side of source BI, conductor It, winding I l of relay R4, contact 5, arm 25, conductor 25, closed switch 27, conductor 25, conductor 25, and back to source BI. The energized relay winding II of R4 will, therefore, throw its armature It to the right against right contact I4 to thereby switch into circuit the other field winding 22. The motor A will now rotate in the right direction, as desired.

.Should itnext be, desired to perform .someother control operation, such as to turn motor A off, to turn motor 13 on, to reverse the direction of operation of either or both motors, or to turn the light on or on, it is only necessary to dial Reset and then the next operation, such as Motor AOff, by appropriate manipulation of the dial mechanism at the control point. In other words, in order to effect a particular sequence of control functions, each must be preceded by dialing Reset, as for example: Beset, lviotor A-On, Reset, Motor BOn, Reset, Motor IB--Off, Reset, Motor A-- Off, Reset, etc.

Although I have shown and described the dial mechanism at the control point to be connected to the controlled mechanism located at a remote point by means of a cable of suitable length, it will be understood, of course, that the system will function equally as well by providing a shorter connecting cable in those instances where it is desired that the mechanisms at opposite ends thereof be in closer proximity to one another, as for example, in the same room, or in the same cabinet.

In Fig. 2 I have shown the present invention applied to a radio receiving system for the automatic control of the tuning and volume thereof from a remote point. For simplicity, the time delay mechanism of Fig. 1 is not shown in detail but is represented by the block 54.

The radio receiver to be controlled from a remote point is represented by the block 18 and may be any conventional type utilizing motoroperated tuning mechanism. For the purpose of illustration, the receiver control mechanism is shown to be the same as that in my application, Serial No. 517,585, filed January 8, 1944, now U. S. Letters Patent 2,383,338, granted August 21, 1945, wherein the motor is of the reversible type and its armature is axially displaced in one direction to effect automatic tuning and in the opposite direction to effect volume control adjustment.

In Fig. 2 the motor armature is indicated at it and the motor field windings at 85} and 8|. The adjustable tuning device of the receiver is represented as a variable condenser 82 with which there is associated a commutator or selector disc 83 provided with conductive segments 8d, 85 and an interposed insulating strip at. 8'! to SI are the p re-set brush contacts for determining the various positions of adjustment of the tuning device. As shown, the brush contacts iii to 9! are conductively connected, respectively, by way of conductors iii to 9!, to the contacts 3 to l, with which the movable contact arm 25 of the selector switch 28 is adapted to co-act. Also adapted to co-act with the switch contact arm 25, when the latter is stepped to any one of the contacts 3 to l, is an elongated, arcuate contact iii; which for that reason extends only for a distance equal to that between contacts Sand i. The arcuate contact 92 is conductively connected to the movable member 2c of switch 2'! by way of a conductor 93. For a purpose which will appear later, a voltage dropping resistance 94 is connected between the latter conductor $3 and the conducting shaft 38 having the switch arm 25 affixed thereto.

The contacts numbered i and 2 of the selector switch are connected respectively to the windings II and i2 of a relay R6, the common terminals of the windings being connected by way of conductor Q to one side'ofa source of operating current constituted bythe transformer 95. The

relay R6 is provided with an armature l3 which is adapted to co-act with one or the other of two fixed contacts 91, 98 connected, respectively, to the voice coils of a pair of loud speakers SI and S2 which are adapted to be energized fromthe audio output AF of the radio receiver 1 3.

The contacts 8 and 9 of the selector switch are connected, respectively, to the motor field windings and ti by way of conductors 99 and Hit. The transformer 96 which constitutes the source of operating current for the motor and relay R6 has one side of its secondary connected to the common terminal of the field windings through a conductor ltll and the other side connected to the fixed contact 28 of the power-restoring switch 21 through a conductor I92.

The manner of operation is as follows: In order to turn the receiver on, the dial plate 52 is manipulated by dialing number 8. As will be understood from the operation previously explained in connection with Fig. l, the pulse transmitting mechanism will advance the switch arm 25 to contact As a consequence the motor circuit through field winding 8i! will be closed as follows: one side of source 96, conductor I62, switch 2! which will close after an appropriate time delay, resistance ti t, shaft til, switch arm 25 resting on contact 8, conductor 99, field winding at, conductor in! and back to the other side of source 98. The operating voltage for the motor having been reduced due to the inclusion of resistance $3 in the above circuit, the motor armature it remains in its axially displaced position to the right and will operate in the proper direction to turn the power switch on and to effect volume increase, as more fully described in my above-mentioned application. The volume of the receiver having been adjusted to the desired extent, the dial mechanism is next manipulated to dial Reset in order that the motor may be deenergiaed and the switch arm 25 returned to its normal position.

,In order to effect a desired tuning adjustment of the receiver, the dial plate 52 will next be suitably manipulated to step along the switch arm 25 to an appropriate contact, such as for example, contact 5. This will complete the following circuit: one side of the source (it, conductor N32, closed switch 2'5, conductor 93, arcuate contact 92, contact arm 25, contact 5, conductor 89, brush contact 3?, commutator segment 55, field winding 85, conductor tilt and back to the other side of the source. The full operating voltage now being effective to energize the motor (resistance t t having been short-circuited) the motor armature will be displaced to the left to establish the friction drive at toil. As a consequence, the motor will rotate the commutator or station selector disc 83, and incidentally the tuning device 82, until the insulating strip 36 arrives in contacting relation with the brush contact 89, atwhich point the motor circuit will be broken, leaving the tuning device in the desired adjusted position,

Should it now be desired to vary the volume up or down, the switch arm 25 will first be returned to its normal or neutral position by manipulating the dial plate to -teset, if this had not been done previously, and then to number 8 or 9, depending upon the function desired to be carried out, in which case the switch arm 25 will be stepped along accordingly, so that the motor circuit will be completed through one or the other of v the motor-reversing field windings 80, 8|.

, 9 Since the latter circuits include the voltage dropping resistance 94, the motor armature will remain displaced to the right to effect the control of the volume either up or down, in the manner more fully described in my above application.

As an additional control, one or the other of the loud speakers Si and S2 may be operative, their selective control being brought about, as will now be clear from the above description, by suitably dialing to position 1 or 2 at the remote point. When so dialed, switch arm 25 will be stepped to either contact i or 2 closing thereby the following circuit which will energize one or the other of relay windings l, 32: one side of source 95, conductor 95, winding H or 22, contact I or 2, switch contact arm 25, shaft 38, resistance 94, conductor 93, closed switch 27:, conductor hi2 and back to the other side of the source. Depending upon which one of the relay windin s is energized the armature 13 will be actuated to contacting relation with contact 9? or 58 to complete thereby the voice coil circuit for speaker SI or $2.

In place of the mechanical time delay mechanism 54 utilized in Figs. 1 and 2 there may be substituted a thermostatic time delay device which I have shown in Fig. 3. The thermostatic time delay is shown generally at H25 and comprises a fixed contact 5535 and a movable contact blade Hi made of two dissimilar materials Sill, 568 having difierent coefficients of eXpansiOn, A heater element E39 is wound over the two pieces of the movable blade and as the heater coil heats these two pieces simultaneously, one of them will lengthen at a different rate than the other thereby causing them to bend to make contact with fixed contact The heater coil is connected across the source B2 through a switch l 19 which is actuated to circuit-closing position by a cam ill affixed to the selector switch shaft 39. the normal position of the switch arm 25, the cam is positioned to permit switch 1 id to remain open. In all other positions of the switch arm the cam will effect closure of the switch to complete the heating circuit for coil I99.

The thermostatic time delay disclosed herein should preferably be so designed that the contacts I05, ltd will not close until after the ratchetdriven switch arm 25 has had time to advance step-by-step to the last contact button. This will prevent premature closing of any of the relay circuits. When Reset is dialed the switch arm will make momentary contact with each button as the arm sweeps over them on the return path but the relays may be so designed that the momentary pulses will not disturb the positions of the several relay armatures.

While I have shown in each case the telephone dial at the control point for transmitting pulses connected to the pulsing solenoid at the remote controlled point by wire or cable it will be under stood by those skilled in the art that this wired link could a radio channel. In this case the telephone dial pulses would be transmitted by radio and picked up by a receiver for actuating the pulse translating mechanism.

The pulse translating mechanism herein described mey be utilized, for example, in a remote controlled submergible torpedo carrier, in which only the antenna rod would be above the surface for picking up the radio signals for actuating the pulsing solenoid. In this case one of the motors of Fig, 1 could be used for operating the rudder,

and the other motor for submerging and surfacing. Additional relays may be used for firing the torpedos or for controlling other devices.

While I have indicated and described certain preferred embodiments for carrying my invention into effect, it will be apparent to one skilled in the art that my invention is by no means limited to the particular organizations shown and described, but that many modifications may be made without departing from the scope of my invention, as set forth in the appended claims.

What I claim is:

1. Control 'mechanism comprising a rotary switch including a movable arm and a plurality of contacts, a plurality of devices to be controlled, each respectively connected to one of said contacts, means including a ratchet Wheel for causing the switch arm to be selectively stepped along step by step from a neutral position to any one of said contacts, a pawl for retaining the ratchet wheel and switch arm in their stepped positions, a time delay device effective as soon as the switch arm begins to step until it reaches the selected contact for preventing actuation of those devices connected to the intermediate contacts, means carried by the ratchet wheel operative at a limiting position of the switch arm to trip the pawl out of engagement with said ratchet wheel, spring means for returning the wheel and arm to neutral position, and additional means carried by the ratchet wheel effective upon its return to neutral position to return the pawl to engaging position.

2. A control system comprising, in combination, dial mechanism for selectively transmitting pre determined numbers of pulses, a stepping solenoid adapted to be energized a number of times corresponding to the number of pulses dialed, a rotary switch including a movable arm and a plurality of contacts, there being a series of a contact and additional contacts, each of the latter corresponding to a diiferent predetermined number of dialed pulses, means actuated upon energization of the solenoid for moving the switch arm stepby-step in a forward direction from the first contact to a contact corresponding to the number of dialed pulses, a device to be controlled connected to each of the switch contacts except the first and last, means under control of the switch actuating means for delaying operation of the device selected to be controlled by the dial mechanism until after the switch arm has been stepped to the corresponding contact, and spring means effective, in the absence of transmitted pulses and after the switch arm has first been stepped to its last contact, to actuate the switch arm in the reverse direction to its first contact.

WILLIAM E. NEWMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,710,126 Vaughan Apr. 23, 1929 2,014,011 Whitby Sept. 10, 1935 2,226 692 Brunner Dec. 31, 1940 2,338,853 Hull Jan. 11, 1944 1,662,877 Almquist Mar. 20, 1928 2,063,354 Thorp Dec. 8, 1936 2,365,284 McClelland Dec. 19, 1944 

